I'm basing the Stars off of overall performance the only reason I didn't give it a five was because of the small defect that I PERSONALLY disliked and feel that it was something that I could have gotten over.I purchased this product after reading many reviews on The Melody Susie website, also after watching many video reviews on the product I decided that I wanted to purchase it. I decided to purchase it off of Amazon because the shipping was faster and it was sold direct from Melody Susie. Upon receiving the e-file I immediately opened it and it had two bars so I put one of my drill bits that I am very familiar with (instead of using one of the ones that came in the box so I can have a better first impression of this e-file) immediately I loved it until I applied pressure I could barely tell that it was slowing down until I released the pressure off of the nail and could immediately hear it speeding back up. Now for others it may not be a problem but to my personal liking and my personal opinion I do not. Other than that the e-file was beautiful sleek design light but not too light it felt good and comfortable while using it. I personally feel that for a beginner nail tech or someone that just does their nails and maybe a few other people's nails it could be fine this problem could be overlooked. I don't think it affects the overall performance of the drill. It didn't do any crazy speeding up or anything it's just when I applied pressure I could tell that it was slowing down and then when I released pressure I could immediately hear it speeding back up. So it was doing its job I guess. Although I've had many other electric files from this brand and even the Scarlet zipped through without a change in speed when applying pressure. I would recommend it to other people if they could get over that small defect. I thought that it may have just been mine that was like that, but after realizing this I went on the Amazon website and seeing other reviews mentioning the same thing. I and being refunded a full refund it should take 3 to 5 business days or had the option to replace it and be sent a new one. However I decided to just take the refund because I personally do not care for the slowdown speed back up to speed. I would recommend buying this e-file if you are not bothered by that, I personally don't think it affects the performance of the machine. maybe it's just me and the others that are a bit picky when it comes to our e-files because many people really really like this electric file. And maybe not all of them are like this. I just have a lot of experience with e-files and how the others have performed in comparison to this one. I'm sure it's a great machine I just didn't give it a chance because of that little tweak.Some of them are good as they were advertisedSo far the drill has been excellent. I spent a little more on this one because it came with the brushless motor,they far superior to brushed motors in every way. The torque is excellent at low speeds and it has never even got past mildly warm let alone hot. The vibration and noise is incredibly low even a full speed, its has actually redefined quiet compared to other drills I've owned. The hand piece is even smaller than I anticipated and it's made of aluminum. A metal headpiece allows for much higher tolerances than plastic ones and that translates into low vibration and quiet operation. It feels great in the hand!! It says it comes with Japanese branded bearings, I'm not sure what that means. Are they made elsewhere and then branded Japanese or are they made in Japan? Whatever they are, they perform very well. The collet system locks and unlocks with a very positive feel and holds the bit very securely. The battery charges quickly, within a couple hours from 1/4 power. I never run batteries down any lower, it seriously affects their longevity. The speed control works very well and speed increases and decreases are smooth throughout the motors rpm range. It runs in reverse just as well. Given its higher price I feel a foot pedal should have atleast been an option to purchase, as it is you need to turn the dial to switch it on and off, a seperate switch for on/off would have gone a long way to. It's the biggest drawback on this unit, for my use anyway. The included bits work but they are about as cheap as you can buy, a $5 value at best. The included handpiece rest is nice, it appears to be a softer silicone of some kind. The handpiece also mounts on the main unit which can clip to your belt. I'm hoping both the belt clip and handpiece mount stand up over time. I included this extra information because they dont give out much in the advertising, I took a big chance on this and I feel it's been worth it in every way that counts. The quality aluminum handpiece is definitely professional in look, size and feel. My other drills will now occupy the closet, I won't miss them. I've only got around 15 hours on this so far, the ultimate test will be time. I'll update here if anything changes. I'm using this for jewelry, light material of silver and gold and polishing. If it will work for me in an industrial application then nails shouldn't bother it at all.I was going to return this. It kept stopping or slowing down when I used it on the nail and took it off. Now I changed the speed and that seems to work. It still slows down and I haven't had a drill do that before.I loved this drill. It just stopped working on me, a little over a month past the return window. I wouldn't cate so much if it didn't work so well and then just n o t h i n g. Also it was not that cheap. I may have to break down and sell a kidney to get a kiara sky drill after all.Unhappy with this unit. It had good reviews, I don't like it. The bits slip out the chuck with a very light tug, that should not happen. It has too much torque. I find that this unit is very powerful and packs a punch. Definitely not good for beginners or anyone without a feather touch. I will not use this unit to prep natural nails, reducing bulk only. Hoping for a refund.Less than a week after the return window closes this thing doesn’t work anymore. It worked well up until today. I’m hoping I can still get a replacement or refund but chances are I’m out of luck.